The valve structure of the present disclosure is in the category or class of valves which are adapted to insertion in a fluid-feed line between a nozzle or discharge orifice and the fluid supply from which fluid is drawn. Such a valve can be used in a multiplicity of lines and is especially adaptable, but not limited to residential fluid systems, self-contained fluid systems and systems having limited space.
The valve herein is described in the context of the utilization of water systems which are found in residential applications, manufactured homes, and recreational vehicles, and is applicable to any system which incorporates a flexible hose connection, whether it be found in a shower, wash basin, bath tub, or the like. The valve of this structure is especially useful in such an environment incorporating fluid systems having a closed or self-contained water supply source from which all utilization of water derives.
There is a heightened concern surrounding the contamination of residential water supply, and especially for self-contained water supply systems. As a result, such systems are subject to rather stringent sanitary codes, which require an insertion in the supply line of valves designed to prevent backflow or re-entry of liquids or solids into the system supply. Backflow is the reversal of the normal and intended direction of flow of water in a pipe line. Siphonage or back siphonage occurs when water in a supply line produces a flow of water in a direction opposite the path of normal flow because of below atmospheric pressure in the supply system.
Valves designed to achieve this result, often referred to as vacuum breaker valves have been in use for several years, and are associated with or capable of permitting the entry of air into the water line under conditions that would otherwise create a siphon condition. In such valves, many complex designs have been used in order to open and close such air vents and to prevent the fluid from leaking through the air vents. An example of such a valve is demonstrated in U.S. Pat. No. 3,951,164.
Increased sanitary code requirements, in particular American Society of Sanitary Engineers “ASSE” section 1014, the performance requirements for hand-held showers (hereinafter “the Code”) have made many, if not all, existing valve designs incapable of passing certification tests under the new provisions. The Code requires a valve that prevents backflow of water when a vacuum pressure is applied to the outlet end of the valve ranging between six (6) inches to twenty-four (24) inches of mercury. Further the Code requires there to be no back-siphonage of water from downstream piping into the supply piping when the check valve seat or disc is fouled to a partially open position by debris, which is simulated in the certification test by a 0.032″ diameter wire while the outlet side of the valve is under a vacuum.
An example of a vacuum breaker valve incapable of satisfying the relatively recent Code requirements is demonstrated in U.S. Pat. No. 4,953,584 issued to Lajos Vegso. The valve found in '584 patent includes a diaphragm having a uniform thickness that is unable to accommodate the flexibility needed for the unrestricted flow of fluid while remaining rigid enough to prevent the collapse of the diaphragm when being subjected to the vacuum levels required by the Code. The '584 patent further fails to provide the needed flexibility in the diaphragm or pressure assistance from either air or liquid when debris is simulated by the 0.032″ diameter wire.
What is needed is an improved vacuum breaker valve assembly capable of satisfying the requirements of the Code as discussed above, resistant to both backflow and back-siphonage.